Circuit interrupter



Jan. 12, 1954 w, M, LEEDS 2,666,117

I CIRCUIT INTERRUP'I'ER Filed Ma 18. 1950 s Sheets-Sheet 2 5 Fig.2.

Winthrop M;Leeds.

zw f v I Patented Jan, 12, 1954 UNITED STATES PATENT OFFICE 2,666,117cmcorr mrnaaur'rnn Winthrop M. Leeds, Pittsburgh, Pa., asslgnor toWestinghouse Electric Corporation, East Pittsburgh, Pat, a corporationof Pennsylvania Application May 18, 1950, Serial No. 162,655

23 Claims.

' This invention relates to circuit interrupters in general, and moreparticularly to arc-extinguishing structures therefor. 1

The general object of my invention is to provide an improved high-speedtype of circuit interrupter or simple construction in which theelectrical circuit passing therethrough may be more eiiectivelyinterrupted than heretofore.

Another object is to provide an improved circuit interrupter in whichthe arc-extinguishing assemblage may be bodily moved near the end or theopemng operation to thereby establish a pair break is establishedadjacent one end or the movable arc-extinguishing assemblage and aninterrupting break is established adjacent the other end or thearc-extinguishing assemblage.

Still a further object is to provide an improved circuit interrupter ofthe type described in the immediately preceding paragraph in whichimproved low4current piston means are incorporated into the structureand in which more effective fluid flow is achieved to more quickly andrapidly bring about extinction of the interrupting arc.

of disconnect gaps in the circuit between the line terminal members andarc-extinguishers.

Still another object is to provide a more eiiective arc-extinguishingstructureior the moderate voltage ranges, for instance kv. to 69 kv., inwhich only a single pressure-generating break and a single interruptingbreak are required to efiectively interrupt the circuit.

The main. advantage of my construction over prior art structures is thehigh speed of operation possible by initially moving only the light-highspeed contacts, while the relatively heavy are extinguishing assemblageremains stationary. Prior art structures utilizinga grid assemblagebridging the terminals have the grid assemblage rigidly connected to thelift rod; consequently, the

arrangement cannot be high speed in operation. with my construction,however, high speed is possible because'only the light contacts aremoved during the arcing period, while the heavy grid is moved only asadisconnecting function.

Another object is to provide an improved high ,speed type of circuitinterrupter of the liquidbreak type in which a pair of terminal bushingsextend into an enclosure wherein a movable arcextinguishing assemblagebridges the terminal bushings in the closed circuit position of thedevice, and in which the arc-extinguishing assemblage bodily moves as aunit'near the end of the opening operation to insert a pair ofdisconnect gaps into the circuit after the high speed contacts havecleared the circuit.

A further object is to provide a circuit interrupter of the typespecified in the immediately preceding paragraph in which the operatingrod effects opening of the contact structure and following apredetermined time delay operates to eilect movement of thearc-extinguishing assem blage to its open disconnect position.

-Another object is to provide an improved liquidbreak circuitinterrupter in which a movable arcestinguishing assemblage bridges apair" or tel? minal bushings wherein a pressure-generating Furtherobjects and advantages willbecome apparent upon reading the followingspecification taken in conjunction with the drawings in which:

Figure 1 is aside elevational view, partially in Fig. 5 is a sectionalview taken along the line VV of Fig. 2;.

Fig. 6 is a sectional view taken along the line VI-VI of Fig. 2;

Fig. '1 is a side elevational view, partially in' vertical section of amodified type of circuit interrupter embodying principles of myinvention and shown in the closed circuit position;

Fig. 8 is a sectional view taken along the line VIII-VIII of Fig. '7;

Fig. 9 is a view similar to that 01 Fig. '7, but showing the contactstructure in the partially open circuit position;

Fig. 10 is a fragmentary sectional view taken along the line X-X of Fig.'1;

Fig. 11 is a fragmentary sectional view taken along the line XI-XI ofFig. 7; and

Fig. 12 shows a modified type of interrupting unit in the open circuitposition.

Referring to the drawings, and; more particularly to Fig. 1 thereof, thereference character I designates a suitable enclosure such as a tankfilled to the level 2 with a suitable arc-extinguishing fluid 3, in thisinstance circuit breaker oil. Depending from the cover 4 of the tank 1are a pair of terminal bushings 5, 0. Secured to the lower ends of theterminal bushings I, 3 are stationary disconnect contact assemblages I,8.

Bridging the space between the stationary disconnect contact assemblagesI, 8 is a movable arcextinguishing assemblage or fluid flow transmittingmeans generally designated by the reference numeral I0, and the internalstructure of which is more clearly shown in Figs. 2-8. Associated withthe movable arc-extinguishing assemblage ID are a pair of rod-shapedmovable arcing contacts II,' I! secured to the outer extremitie of aconducting cross-bar l3, the latter being reciprocally movable in avertical direction by an insulating lift rod i 4.

The insulating rod I4 is actuated by suitable mechanism, not shown,responsive to manual operation or to the existence of'overloadconditions existing in the circuit controlled by the interrupter.

Referring more particularly to Fig. 2, it will be noticed that securedto the top of the arcextinguishing assemblage ID are a pair of movabledisconnect contacts |5, |5 which enter contact housings II, II, thelatter being threadedly secured and clamped to the lower ends ofterminal studs I9, 20 passing interiorly through the terminal bushings5, 5.

Disposed interiorly within the contact housings l1, iii are contactsegments 3| biased radially inwardly by flexible leaf springs 22 andserving to electrically interconnect the stationary disconnect contacts23 with the movable disconnect contacts l5, l5.

As shown more clearly in Fig. 2, the movable disconnect contacts l5, IIare integrally formed with cap structures 24, 35' secured by bolts 26-to the top insulating plate 21 of the movable arcextinguishingassemblage Ill. Preferably I provide arcing rings 28, 23 into which Ithreadedly secure the lower extremities of the bolts 25.

Disposed interiorly within the cap structures 24, 25 are a plurality ofcontact segments 30 biased radially inwardly by flexible leaf springs 3|to bridge the movable disconnect contacts 5, i6 with the rod-shapedmovable arcing contacts II, II. Preferably, apertures 32 are provided atthe top of the cap structures 24, 25 controlled by a washer-shapedmovable valve 33. In the closed position of the interrupter, as shown inFig. 2, the valve 33 rests upon the top of the contact segments 30permitting the apertures 32 to be open and allow gas to escape as theassemblage l0 fills with fluid. However, during high-pressure conditionswithin the movable arc-extinguishing assemblage III, the valve 33 isforced by the pressure upwardly away from the contact segments 30 toclose the apertures 32 and thereby eflectively close thepressure-generating arc passage 34 at its upper end and also close theinterrupt-- ing arc passage 35 at its upper end.

Associated with the top insulating plate 37 of the movablearc-extinguishing assemblage I0 is a combination dashpot and low currentpiston means generally designated by the referenc numeral 36. The pistonmeans 38 includes an insulating cylinder 3'! having its lower end 38threadedly secured to the top plate 21 of the assemblage Hi. The upperend of the cylinder 31 is provided with an inwardly extending flangeportion 39 which serves as the upper seat for an insulating washer 43.The washer 4|! in turn provides the upper seat for a compression spring4|, the lower end of which seats within an annular recess 42 provided inan insulating plate 43, the latter being disposed immediately adjacentto the top insulating plate 31. An enlarged portion 44 of the operatingrod l4 strikes the plate 43 near the end of the opening operation 3 toforceably drive the movable arc-extinguishing assemblage |3 to itsdisconnect position as shown by the full lines inFlg. 1.

The interrupting structure for the arc-extinguishing assemblage III willnow be described. As noticed in Figs. 2 and 3, the arc-extinguishingassemblage l3 includes a plurality of suitably formed insulating platesdisposed in contiguous relation by a plurality of insulating tie rods 45(Fig. 4) Immediately below the insulating plate 43 is an insulatingplate 46, the configuration of which is more clearly shown in Fig. 4.With reference to Fig. 4', it will be observed that the insulating plate48 is provided withan elongated cutout portion 41. Disposed within thecutout portion 41 is an insulatingplate 43, which, in conjunction withthe plate 46, forms two fluid flow passages 49 which interconnect thepressure-generating arc passage or pressure-generating chamber 34 withthe interrupting arc passage or interrupting chamber 35. It will beobserved that the insulating plate 48 has an enlarged aperture 50provided therethrough through which passes the operating rod |4.

Disposed immediately below the insulating plate 43 is an insulatingplate 5|, the configuration of which is more clearly shown in Fig. 6.With reference to Fig. 6, it will be noticed that the insulating plate5| has apertures 52, 53 provided therethrough, through which pass themovable contacts II, II. Also, the plate 5| has provided therein theaperture 50, which also was the case in Fig. 4, accommodating travel ofthe operating rod l4. Apertures 54 are provided in the several plates toaccommodate the insulating tie rods 45, the latterserving the purpose ofrigidly holding the plates together in contiguous relationship.

Immediately below the insulating plate 5| is an insulating plate 55, theconfiguration of which is more clearlyshown in Fig. 5. Asnoticed in thisfigure, the insulating plate 55 is composite, being formed by thecooperation oi Y :3. insulating plates 53, 51. Each of these plates 58,51 is'provided with the apertures 54 to accommodate the insulating tierods 45. The insulating plate 55 is provided with a cutout portion 53 asshown. It will be observed that the plates 53, 51 are spaced apart toprovide two outwardly extending discharge passages 59, 60 leading indiametrically opposed directions out of the assemblage Ill. The functionof the discharge passages 59, 60 will become more apparent hereinafter.

Immediately below the insulating vent plate 55, is a second orificeinsulating plate 5|, then follows an inlet insulating plate 46, andanother orifice insulating plate 5|, a vent plate 55, and anotherorifice insulating plate 5|.

Immediately below the lower orifice plate 5| is an insulating plate 6|having a configuration similar to that of the orifice insulating plate5| with the exception that the apertures 52, 53 are considerablyenlarged as shown at 52, 53. In addition, the insulating plate 5| isprovided with a centrally disposed annular aperture 54 whichaccommodates an accelerating compression spring 55.

The lowest plate of the movable arc-extirguishing assemblage I0 isdesignated by the ref erence character 65. It is similar in constructionto that of the insulating plate 8| but in s place of the enlargedapertures 62, I3 is provided with only small apertures :61.- 33, throughwhich pass the rod-shaped arcing contacts II, it with only slightclearance.

The operation of my improved circuit interrupter will now be explained.In the closed circuit position of the interrupter, as shownin Fig. 2,the electrical circuit therethrough includes terminal stud i3,stationary disconnect contact-23. contact segmentsll, movable disconnectcontact li. contact segments 33, movable arcing contact If, conductingcross-bar l3, movable arcing contact I I, contact segments 33, movabledisconnect contact I6, contact segments II associated with theright-hand stationary disconnect contact assemblage I. stationarydisconnect contact 23 associated with the righthand stationarydisconnect contact assemblage I, to the right-hand terminal stud II ofthe interrupter.

when it is desired to effect opening of the interrupter. or in responseto overload condi-- tions existing in the electrical circuit controlledby the interrupter, suitable mechanism, not shown. is actuated to causerapid downward motionof the insulating lift rod l4. The'downwardmovement of the insulating lift rod i4 is accelerated by theaccelerating springs associated with the pole unit mechanism, not shown,

. blage It at the time of initial downward movement of the arcingcontacts M, ii. These two forces are: (1) Upward force exerted bycompression spring 65 upon the assemblage l0, and

(2) Internal gas pressure within the assemblage times the area of themoving arcing contact tips II, II. J

The downward movement of the contacts II, I! causes apressure-generating are 69 to be established between the upper tip ofthe movable contact II and the arcing ring 23 within thepressure-generating arc passage 34, as shown more clearly in Fig. 3.Simultaneously an interrupting are 13 is established between the uppertip of the movable contact I! and the arcing ring 23 within theinterrupting arc passage 35. Thisdrawing of the two arcs 63, 13 occursbefore the enlargedv portion 44 associated with the operating rodi4=enters the dashpot 36.

During relatively high current conditions, the pressure generated by thepressure-generating are 63 withinzithe pressure-generating arc passage34 closes the valve 33 against the apertures 32 and drivesarc-extinguishing fluid, in this instance circuit breaker oil disposedwithin the assemblage it, toward the right, as indicated by the arrows Hin Fig. 4, through the inlet passages 43 and into the interrupting arcpassage 35. The, oil, forced through the passages 43, strikes theinterrupting are 13 and comes into intimate contact therewith by beingcompelled to pass through the apertures or orifices 53, before the oilis permitted to exhaust out of the assemblage l3 throughthediametrically opposed exhaust passages 63, 63 as provided by thecomposite vent plate II. The direction of the outward flow of oil isindicated by the arrows II of "Fig. 5.

It will be-observed that there are two inlet plates 46 which provide oilto passinto the interrupting passage 36 at a plurality of levels. Itwill also be noted that the discharge passages 63 63 associated witheach vent plate 66 are disposed at two or a plurality of: intermediatelevels. Obviously, for a higher voltage application there could beprovided more of the inlet plates 46 and more of the intermediatelydisposed vent plates 55.

During the interruption of relatively low amperage currents, where thegas generated by the low current pressure-generating arc is inadequateto establish suificient pressure within the pressuregenerating arcpassage 34, reliance may be had upon the piston means or dashpot 36. Inother words, following predetermined downward travel of the operatingrod I4, the enlarged portion 44 thereof enters the dashpot 36 andforces'the piston 43 downwardly against the pressure of spring 4| tomove fluid, in this instance oil, .out of the piston chamber 13, asformed by the cylinder 31, downwardly through the apertures 50 providedin the several plates, and toward the left, as indicated by the arrows14 of Fig. 3, into the pressure-generating arc passage 34. This oil,forced into the pressure-generating arc passage 34 by the actuation ofthe piston means 36, strikes the pressure-generating are 69 toeffectively bring interrupting action to bear thereupon. Furthermore,this oil forced from the piston chamber I3 passes through the apertures52 associated with the pressure-generating arc passage 34 and is sentonwardly through the inlet passages 49, provided by the inlet plates 46,to strike the interrupting are 10 and to become exhausted from the unitIt in the manner heretofore described.

From the foregoing, it will be apparent that during the interruption ofhigh currents the circuit will be interrupted by the time the enlargedportion 44 of the operating rod l4 enters the dashpot 36 to forciblydrive the movable arcextinguishing assemblage l0 downwardly to its opencircuit disconnect position, as shown in Fig. 1. In the case ofinterrupting high currents, the actuation of the piston means 36 merelyserves to flush contaminated oil out of the unit In, interruption of thearcs already having taken place. During the interruption of lowcurrents, where sufflcient pressure is not generated within thepressure-generating arc passage 34, reliance may be had upon the pistonmeans 36 for the sending of the requisite quantity of oil toward thepressure-generating are 63 and then onwardly toward the interrupting arcHi. It will be noticed that during such low current interruption,effective interrupting conditions are brought to bear upon both arcs 63,10 by the actuation of the piston means 36, the oil from the pistonchamber 13 'being sent sequentially through the pressure are 63 and thenonwardly toward the interrupting are 70, to thereafter become exhaustedfrom the unit III through the discharge passages 53, 60.

As in the case of high current interruption, at the end of the actuationof the piston means 36. the movable arc-extinguishing assemblage i0 isforceably moved downwardly to its open circuit disconnect positionwherein two insulating disconnect gaps are inserted into thecircuit, inaddition to the gaps already provided between the contacts H, H and thearcing rings 28, 29.

.the closing operation. the-lift rod ll moves upwardly. v Because of thepresence of the accelerating compression spring OI, the movablearc-extinguishing assemblage il causes re-engagement between-thecontactsII. II and I, It prior to closing of the arcing contacts. Thus, thedisconnect, contacts are re-engaged before engagement of the arcingcontacts.

The foregoing description indicates how i. have provided an improvedcircuit interrupter of the type particularly adaptable for moderatevoltcable thereto. For instance, it will be readily apparent to oneskilled in the art that repetition of the plate structure may be'provided to adapt the structure for higher voltage application, that isproviding three or more inlet plates It, and three or more vent platesII to suit the particular voltage application. However. the structure issimple and may be readily adaptable to moderate voltage applicationswhere a single pressure-generating arc and a single interrupting areassociated with eachpole of the interrupter are sufiicient to eflectcircuit interruption.

Referring to Figs. 7 through 11. it will be observed that I haveprovided a somewhat simpler and cheaper embodiment of my invention.Referring to Fig. 7, it will be'noticed that the arcing contacts ii, I!in this instance pass upwardly entirely through the modified movablearc-extinguishing assemblage 18. As noticed in Figs. 7 and 8, the upperends of the arcing contacts II, II engage finger contacts 19, soassociated with the contact housings II, III of the interrupter. Thesecontact housings O I, 82 are threadedly secured and clamped tothe lowerends of the terminal studs l9, II.

In this particular embodiment of my invention, a pair of cooperable liftrods 83, 84 are provided, being secured together at their lower ends bya pair of brackets ll, Ila afiixed to opposite sides of the conductingcrossbar i8. A support It is secured by bolts II to the lower end of themovable assemblage l8. interposed between the support 86 and thebrackets It, 85a are a pair of compression springs 88 which serve thesame function as the accelerating compression spring previouslydescribed in connection with the first embodiment of my invention.

The movable arc-extinguishing assemblage I8 is simplified in thisconstruction of my invention by being made out of a section of aninsulating cylinder Cl. An insulating disc 00 is threadedly secured tothe left-hand end of the assemblage II as shown in Fig. 7. Theinterrupting arc passage 35 is in this particular embodiment of myinvention formed by a sub-assemblage 9! of suitably formed insulatingplates, the construction of which is more readily apparent uponexamination of Figs. 10 and 11.

The sub-assemblage 0| of insulating plates includes a top insulatingplate 82 having a configuration more clearly shown in Fig. 10. The plateII has a U-shaped cutout portion 93 removed therefrom. Below theinsulating plate I is an insulating orifice'plate having a configurationmore clearly shown in Fig. 10 and being designated by the referencecharacter 04. The plate 84 has an aperture or orifice 95 formed therein.

Below the orifice plate 04 is an insulating composite vent plategenerally designated by the reference character 90 and more clearlyshown in Fig. 11. The vent plate 06 includes two plates .1, ll spacedapart and cemented in position awithrespecttotheotherplatesoftbesub-assemblage ll so as to formdiametricallyopposed vent passages ll, Ill leading outof the!assemblag'e ll. Suitable apertures III are provided through the tube llto register with thevent passages ".10.. as more clearly shown in Figs.Below the vent plate 00 is a second orifice N which is followed by asecond inlet plate 02. Then follows anorifiee plate .a vent plate It andanother orifice plate It. An inlet plate I! constitutes the lowest plateof the sub-assembl'ageli.

The several plates of the sub-assemblage ll are cemented together in apreliminary process step and the sub-assemblage Ii is then machined tohavea cylindrical contour, as indicated in Fig. 8. When this isdone. thesub-assemblage .li may be inserted into the right-hand end of the tubeII and so positioned that thevent passages II, I register with theapertures ill providedthrough the tube II. If desired. the subassemblageI may be cemented into the proper position relative to the insulatingtube It or inserted therein by a press fit. when this is done, a seconddisc ill, similar to the disc I. may be threadedly secured at III to therighthand end of the tube II to securely hold the sub-assemblage I inplace.

The operation of the modified type of interrupter will now be explained.In the closed circuit position, the electrical circuit extending throughthe interrupter includes terminal stud l0, stationary contact fingers1!, movable contact Ii, conducting cross-bar ll. movable contact l2,stationary finger contacts 80 to the terminal stud 20. During theopening operation, the lift rods l8, ll are moved downwardly together inthe same manner as the lift rod 14 of Fig. i. This initially effectsexpansion of the accelerating compression springs II to thereby causethe assemblage II to remain stationary and to cause rapid downwardseparating motion of the rod-shaped contacts II. I! away from the fingercontacts II, II to draw a pressure-generating are and an interruptingare I. as shown in Fig. 9. The pressure-generating are 00 reacts uponthe oil disposed within the tube II to generate pressure within thepressuregenerating chamber A at the left-hand end of the assemblage II.The pressure generated within the pressure-generating chamber A forcesoil to move in the direction of the arrows "M of Fig. 9 and Fig. 10.This oil fiows upwardly and downwardly through the apertures or orifices98 provided by the orifice plates 04 to thereby come into intimatecontact with the interrupting arc ll.

, assemblage ll through the oppositely disposed vent passages l9. plates86.

In this embodiment of myinvention, it will be noticed that I have notprovided any piston means, reliance being had entirely upon lengtheningof the pressure-generating and interrupting arcs 89, 10 to eflectcircuit interruption during low current conditions.v Duringjhigh currentconditions, the pressure generated at the pressure-generating arc iswithin the pressuregenerating chamber ll will be adequate to effect therequisite flow of oil into the interrupting about extinction of the in-It then passes out of the IN provided by the vent ably drive the samedownwardly to the fully open circuit position or the interrupter, notshown. In this position naturally the assemblage I8 will be spaced awayfrom the contact housings 8|, 8! in a manner similar to that shown inFig. 1.

It will be observed that during the closing operation, the acceleratingsprings 88 will cause the assemblage 18 to strike the contact housingsll, 82 prior to contact engagement. Thereafter, the contacts II, I! willengage the stationary finger contacts 19, 80 to complete the electricalcircuit passing through the interrupter.

It will be noted that this embodiment of my invention is simple inconstruction and high speed in operation. Further, few parts areinvolved, and maintenance is easily achieved by the ready accessibilityof the several parts.

Fig. 12 shows a further embodiment of my invention identical in allrespects to the embodiment of Figs. 7-11 except the acceleratingcompression springs 88 are omitted. Theoperation is the sameasheretofore described in connection with Figs. 7-11, but inertia isrelied upon to keep the tube 88 up during the interruption period. Whenthe tube 88 does move down, either by being struck by band I05, or bygravity after a delay, then it will be notced that a larger disconnectgap X is obtained than was possible in Figs. 7-11 using the springs 88.This is so because the springs 88 held the tube 89 up against the bandI05 in the fully open position of the interrupter.

Further, it will be noticed that in the embodiment of Fig. 12 reclosingduring the closing opsets of finger contacts are required. Also, it willbe noted that the arcing contacts are fiat blades entering a pair ofstationary fingers instead of round rods and finger clusters as inFig. 1. The compression springs 88 may be omitted, as in Fig. 12, andinertia relied upon to keep the tube 89 up during the arcing period.

It is to be noticed that the extreme high speed of operation is possiblebecause initially only the relatively light moving contacts are moved,the relatively heavy extinguishing assemblage remaining stationaryduring the arcing period.

Although I have shown and described specific structures, it is to beclearly understood that the same were for the purpose of illustrationand changes and modifications may be made therein by those skilled inthe art without departing from the spirit and scope of the appendedclaims.

I claim as my invention:

1. A circuit interrupter including an enclosure, a pair of terminalbushings extending within the enclosure and having stationary contactsassociated therewith, a pair of movable rodshaped contacts, a conductingcross-bar mechanically and. electrically interconnecting the pair ofmovable contacts, an operating rod for' actuating the cross-bar, amovable arc-extinguishing assemblage, the movable contacts being movablewith the operating rod and actuated thereby, said movable contacts beingmovable substantially through the assemblage inthe closed circuitposition or the interrupter, the arc-extinguishing assemblage having alost-motion connection with respect to the cross-bar and operating rod,and the arc-extinguishing assemblage remaining. stationary adjacent thetwo stationary contacts during the initial portion of the openingoperation while the two movable contacts move away from the stationarycontacts to draw arcs within the then stationary arc-extinguishingassemblage.

2. A circuit interrupter including an enclosure, a pair of terminalbushings extending within the enclosure and having stationary contactsassociated therewith, a pair of movable rodshaped contacts, a conductingcross-bar mechanically and electrically interconnecting the pair ofmovable contacts, an operating rod for actuating the cross-bar, amovable arc-extinguishing assemblage, the movable contacts being movablewith the operating rod and actuated thereby, said movable contacts beingmovable substantially through the assemblage in the closed circuitposition of the interrupter, the arc-i extinguishing assemblage having alost-motion connection with respect to the cross-bar and operating rod,biasing means biasing the arc-extinguishing assemblage in thedirectionrof the stationary contacts during the opening operation, andthe arc-extinguishing assemblage re- I maining stationary adjacent thetwo stationary contacts during the initial portion of the openingoperation while the two movable contacts move away from the stationarycontacts to draw arcs within the then stationary arc-extinguishingassemblage.

3. A circuit interrupter including an enclosure, a pair of terminalbushings extending within the enclosure and having stationary contactsassociated therewith, a pair of movable rodshaped contacts, a conductingcross-bar mechanically and electrically interconnecting the pair ofmovable contacts, an operating rod for actuating the cross-bar, amovable arc-extinguishing assemblage having motion relative to themovable contacts, the movable contacts being movable'with theoperatingrod and actuated thereby, and said movable contacts being movableentirely through the arc-extinguishing assemblage in the closed circuitposition of the interrupter to engage the stationary contacts.

4. A circuit interrupter including an enclosure, a pair of terminalbushings extending within the enclosure and having stationary contactsassociated therewith, a pair of movable rod-shaped contacts, aconducting cross-bar mechanically and electrically interconnecting thepair of movable contacts, an operating rod for actuating the cross-bar,a movable arc-extinguishing assemblage, the movable contacts beingmovable with the operating rod and actuated thereby, said movablecontacts being movable substantially through the assemblage in theclosed circuit position of the interrupter, the arc-extinguishingassemblage having a lost-motion connection with respect to the cross-barand operating rod, a pressure-generating are being established adjacentone stationary contact, an interrupting are being established adjacentthe other stationary contact, the arc-extinguishing assemblage servingas fluid flow com- .municating means interconnecting the two arcsinitial portion oi the opening operation while the two movable contactsmove away from the stationary contacts to draw arcs within the thenstationary arc-extinguishing assemblage.

5. A circuit interrupter including an enclosure, a pair of terminalbushings extending within the enclosure and having stationary contactsassociated therewith, a pair of movable rod-shaped contacts, aconducting cross-bar mechanically and electrically interconnecting thepair 01' movable contacts, an operating rod for actuating the cross-bar,an arc-extinguishing assemblage having movement relative to thecross-bar, the movable contacts being movable with the operating rod,said movable contacts being movable through the arc-extinguishingassemblage in the closed circuit position of the interrupter to engagethe stationary contacts, a pressure-generating are being establishedadjacent one stationary contact, an interrupting are being establishedadjacent the other stationary contact, and the arc-extinguishingassemblage serving as fluid flow communicating means interconnecting thetwo arcs to thereby effect their extinction.

8. A circuit interrupter inc uding an enclosure, a pair of terminalbushings extending within the enclosure and having stationary contactsas'soci-.

ated therewith, a pair of movable rod-shaped contacts, a conductingcross-bar mechanically and electrically interconnecting the pair oimovable contacts, an operating rod for actuating the cross-bar, anarc-extinguishing assemblage, the movable contacts being i'lxedlysecured to and movable with the operating rod, said movable contactsbeing movable substantially through the assemblage in the closed circuitposition 01 the interrupter, the arc-extinguishing assemblage having alost-motion connection with respect to the cross-bar and operating rod,movable disconnect contact means carried by the movable arcextinguishingassemblage externally thereof to engage the stationary contacts, and themovable contacts-engaging the disconnect contact means internally oi thearc-extinguishing assemblage.

7. A circuit interrupter including an enclosure, a pair ofterminal'bushings extending within the enclosure and having stationarycontacts associated therewith, a pair of movable rod-shaped tactsassociated with the terminal studs, a pair of rod-shaped movablecontacts, a cross-bar connecting the movable contacts, an operating rodfor actuating the cross-bar, a pressure-generating are being establishedadjacent one stationary contact and an interrupting are beingestablished adjacent the other stationary contact, and fluid flowtransmitting means having ,a lost-motion connection with the cross-barand carried therewith during the closing operation.

9. A circuit interrupter including a pair of 4 spaced terminal studs, apair of stationary contacts associated with the terminal studs, a pair01 rod-shaped movable contacts, a cross-bar connecting the movablecontacts. an operating rod for actuating the cross-bar, apressure-generating are being established adjacent one stationarycontact and an interrupting are being established adjacent the otherstationary contact. and fluid flow transmitting means having alost-motion connection with the cross-bar and carried therewith duringthe closing operation. and biasing means biasing the fluid flowtransmitting means away from the cross-bar.

, 10. A circuit interrupter including an enclosure, a pair oi terminalbushings extending within the enclosure and having stationary contactsassociated therewith, a pair of movable rod-shaped contacts, aconducting cross-bar mechanically and electrically interconnecting thepair oi movable contacts, an operating rod for actuating the cross-bar,an arc-extinguishing assemblage, the movable contacts being iixedlysecured to and movable with the operating rod. said movable contactsbeing movable substantially through the assemblage in the closed circuitposition of the interrupter, the arc-extinguishing assemblage having alost-motion connection with respect to the cross-bar and operating rod,piston means ,associated with the arc-extinguishing assemblage, theoperating rod carrying an actuating portion, and the actuating portionactuating the piston means during the opening operation.

11. A circuit interrupter oi the liquid break Type including a pair ofspaced stationary contacts, a pair of rod-shaped movable contacts, across-bar connecting the pair of movable contacts, and operating rodhaving an actuating portion for operating the cross-bar, one movablecontact establishing a pressure-generating arc, the other movablecontact establishing an interrupting arc, fluid flow transmitting meanssubstantially enclosing the two arcs and having a lost-motion connectionwith the cross-bar, piston means carried by the fluid flow transmittingmeans, and the actuating portion of the operating rod actuating thepiston means and also moving the fluid flow transmitting means to theopen circuit position. o

12. A circuit interrupter including a pair 0! spaced terminal studs, apair of stationary contacts associated with the terminal studs, a pairof rod-shaped movable contacts, a cross-bar connecting the movablecontacts, an operating rod for actuating the cross-bar, apressure-generating arc being established adjacent one stationarycontact and an interrupting are being established adjacent the otherstationary contact and fluid flow transmitting means only ventedadjacent one end thereof having a lost-motion connection with thecross-bar and carried therewith during the closing operation. I

13. A circuit interrupter including a pair of spaced terminal studs, apair ot stationary contacts associated with the te minal studs, a pairof rod-shaped movable contacts, a cross-bar connecting the movablecontacts, an operating rod for actuating the cross-bar, apressure-generating arc being established adjacent one stationarycontact and an interrupting arc being established adjacent the otherstationary contact, fluid flow transmitting means having a lost-motionconnection with the cross-bar and carried therewith during the closingoperation, and piston means carried by the fluid flow transmitting meansand operated by the operating rod.

14. A circuit interrupter including a pair 0! 13 spaced terminal studs,a pair of stationary contacts associated with the terminal studs, a,pairoi rod-shaped movable contacts, a cross-bar connecting the movablecontacts, an operating rod necting the movable contacts, an operatingrod for actuating the cross-bar, a pressure-generating are beingestablished adjacent one stationary contact and an interrupting arebeing established adjacent the other stationary contact, and fluid flowtransmitting means having a lost motion connection with the cross-barand carried therewith during the closing operation, the two movablecontacts being movable completely through the fluid flow transmittingmeans in the closed circuit position of the interrupter, and biasingmeans biasing the fluid flow transmitting means away from the cross-bar.

16. A circuit interrupter including a pairof spaced terminal studs, apair of stationary contacts associated with the terminal studs, a pairof rod-shaped movable contacts, a cross-bar connecting the movablecontacts, an operating rod for actuating the cross-bar, apressure-generating are being established adjacent one stationarycontact and an interrupting are being established adjacent the otherstationary contact, fluid flow transmitting means having a lostmotionconnection with the cross-bar and carried therewith during the closingoperation, and the fluid flow transmitting means coming to rest in theopen position of the interrupter immediate- 1y adjacent to thecross-bar.

17. In a circuit interrupter of the liquid break type, a tank containingan arc extinguishing liquid, two terminal bushings extending into thetank, relatively stationary contact means disposed at the interior endof each terminal bushing, a movable arc extinguishing assemblageincluding a pressure-generating unit and an interrupting unithydraulically interconnected by a conduit means, movable contact meansincluding a movable pressure-generating contactand a movableinterrupting contact, a movable conducting cross-bar electrically andmechanically connecting the two movable contacts, an operating rod fixedto the cross-bar to cause the actuation of the same, and a lost-motionconnection between the movable contact means and the movable arcextinguishing assemblage so that during the initial portion of theopening operation only the movable contact means first moves andsubsequently, after an appreciable delay, the arcextinguishingassemblage moves therewith.

18. In a circuit interrupter of the liquid'break type, a tank containingan arc extinguishing liquid, two terminal bushings extending into thetank, relatively stationary contact means disposed at the interior endof each terminal bush ing, a movable arc extinguishing assemblageincludingapressure-generating unit and an interrupting unithydraulically interconnected by 1 4 a conduit means, movable contactmeans including a movable pressure-generating contact and .a movableinterrupting contact, a conducting cross-bar electrically andmechanically connecting the two movable contacts, an operating rod fixedto the cross-bar to cause the actuation of the same, a lost-motionconnection between the movable contact means and the movable arcextinguishing assemblage, means biasing the movable arc extinguishingassemblage to the closed circuit position, and the operating rod havingan actuating portion to iorceably drive the extinguishing assemblagetherewith during the final portion of the opening operation.

19. In a circuit interrupter of the liquid break type, a tank containingan arc extinguishing liquid, two terminal bushings extending into thetank, relatively stationary contact meansdisposed at the interior end ofeach terminal bushing, a movable arc extinguishing assemblage includinga pressure-generating unit and an interrupting unit hydraulicallyinterconnected by a conduit means, movable contact means including amovable pressure-generating contact and.

a movable interrupting contact, a conducting cross-bar electrically andmechanically connecting the two movable contacts, an operating rod fixedto the cross-bar to cause the actuation of the same, a lost-motionconnection between the movable contact means and the movable arcextinguishing assemblage so that during the initial portion of theopening operation only the movable contact means first moves andsubsequently, after an appreciable delay, the arc-extinguishingassemblage moves therewith, and the movable contacts being movablethrough the units to engage the stationary contact means in the closedcircuit position 01' the interrupter.

20. In a circuit interrupter oi the liquid break type, a tank containingan arc extinguishing liquid, two terminal bushings extending into thetank, relatively stationary contact means disposed at the interior endof each terminal bushing, a movable arc extinguishing assemblageincluding a pressure-generating unit and an interrupting unithydraulically interconnected by a conduit means, movable contact meanshaving a lost-motion connection with the assemblage including a movablepressure-generating contact and a movable interrupting contact, aninsulating operating rod for actuating the assemblage and the movablecontact means, and the assemblage remaining momentarily stationaryduring the initial portion of the opening operation while the movablecontacts move relative thereto establishing arcing within thepressure-generating and interrupting units.

21. In a circuit interrupter of the liquid break type, a tank containingan arc extinguishing liquid, two terminal bushings extending into thetank, relatively stationary contact means disposed at the interior endof each terminal bushing, a movable-arc extinguishing assemblageincluding a pressure-generating unit and an interrupting unithydraulically interconnected by a conduit means, movable contact meansincluding a movable pressure-generating contact and a movableinterrupting contact, a conducting cross-bar electrically andmechanically connecting the two movable contacts, an operating rod fixedto the cross-bar to cause the actuation of the same, and a lost-motionconnection be tween the movable contact means and the movable arcextinguishing assemblage, movable disconnect means associated with theend of each unit and contacting the stationary contact means connectmeans interlorly of the units during the opening operation.

22. In a circuit interrupter oi the liquid break type, a tank containingan arc extinguishing liquid, two terminal bushings extending into thetank, relatively stationary contact means disposed at the interior endor each terminal bushing, a'movable arc extinguishing assemblageincluding a pressure-generating unit and an interrupting unithydraulically interconnected by a conduit means, movable contact meansincluding a movable pressure-generating contact and a movableinterrupting contact, a conducting cross-bar electrically andmechanically connecting the two movable contacts, an operating rod fixedto the cross-bar to cause the actuation of the same, a lost-motionconnection between the movable contact means and the movable areextinguishing assemblage, movable disconnect means associated with theend of each unit and contacting the stationary contact means in theclosed V circuit position, the movable contacts pulling away from themovable disconnect means interiorly or the units during the openingoperaing, a movable arc extinguishing assemblage including apressure-generating unit and an interrupting unit hydraulicallyinterconnected by .a conduit means, movable contact means including amovable pressure-generating contact and a movable interrupting contact,a conducting cross-bar electrically and mechanicallwconnecting the twomovable contacts, an operating rod iixed to the cross-bar to cause theactuation of the same, a lost-motion connection between the movablecontact means and the movable are extinguishing assemblage, movabledisconnect means assoeiated'with the end of each unit and contacting thestationary contact means in the closed circuit position, the movablecontacts pulling away from the movable disconnect means interiorly orthe units during the opening oporation, the movable disconnect meansenclostion, and the movable disconnect means enclosing said ends of theunits to increase the pres sure formed therein during the openingoperation.

23. Ina circuit interrupter of the liquldbreaktype, a tank containing anarc extinguishing liquid, two terminal bushings extending into the,

tank, relatively stationary contact means disposed at the interior endof each terminal bushing said ends oi the units to increase the pressureformed therein during the opening operation, and valve means associatedwith the movable disconnect means to vent the units at the end of theopening operation.

. WIN'I'HROP M. LEEDS.

References Cited in the ills of this patent UNITED s'rA'ms PATENTSNumber Name Date 1,530,444 Trencham -1--- Mai-:17, 1925 2,156,450 ColeMay 2, 1939 2,419,106 Baker et a1 Apr. 15, 1947 FOREIGN PATENTS NumberCountry Date 661,181 Germany Mar. 9,1932 413,751 Great Britain July 26,1934

